Double-ended electric lamp and associated u-shaped metal clip



16, 1967 v R. J. AYRES ETAL 3,320,466

DOUBLE-ENDED ELECTRIC LAMP AND ASSOCIATED U-SHAPED METAL CLIP Filed Oct.25, 1959 ITWQTWTOTS: lQe gi naLd d. Agres, Paul, Vargo United StatesPatent 3,326,466 DOUBLE-ENDED ELETRIC LAMP AND ASSOCI- ATED ill-SHAPEDMETAL (CLIP Reginald J. Ayres, Shakers Heights, and Paul Vargo,

Lyndhurst, Ohio, assignors to General Electric Company, a corporation ofNew York Filed Oct. 23, 1959, Ser. No. 848,282 1 Claim. (Cl. 313F618)This invention relates to electrical devices such as incandescent lampsand gaseous discharge devices, and more particularly to electricaldevices of the double-ended type having a tubular or otherwise elongatedenvelope or bulb provided with terminal contacts at its opposite ends.The invention is particularly adapted to relatively small size orminiature type lamps and devices such as are used, for instance, inautomobile dome or dash lighting, or for tail lamps.

The production of a satisfactory inexpensive doubleended miniatureincandescent lamp of simple construction and adapted for use with simpleand inexpensive sockets such as the clip-type sockets commonly used forcartridge fuses, for example, has been a continuing problem in thelamp-making art. Prior proposed lamp constructions of this general typehave not been entirely satisfactory for various reasons such as theirunadaptability to machine manufacture, or their requirement forproduction methods which resulted in a high percentage of rejects due tofaulty seals, etc., or the formation of socalled gassy lamps. Also, suchprior proposed doubleeuded lamps were generally provided with separatemetal base members sealed to each end of the lamp which therefore addedto the number of parts as well as the number of manufacturing operationsrequired to fabricate the lamp, in addition to adding to themanufacturing cost thereof.

It is an object of our invention, therefore, to provide a double-endedelectric lamp or similar device of very simple and inexpensiveconstruction and easy to make, and which is readily adaptable to machinemanufacture.

Another object of our invention is to provide a doubleended electriclamp or similar device of the baseless type having its terminal contactsconstituted by the leadin wires of the lamp.

Briefly stated, in accordance with one aspect of the invention, the twolead-in wires of an incandescent lamp are sealed into opposite ends ofan elongated glass bulb or envelope, through protruding fiat externalstem press portions on the envelope at its opposite ends, with the saidlead-in wires protruding endwise from and bent around the end of therespective stern press portion to extend back therealong and lie more orless fiat against one of the fiat side faces of the stern press within agen erally U or V-shaped longitudinal groove therein the depth of whichis sufficient to entirely conceal the lead-in wire beneath the surfaceof the fiat side of the stem press so as to be protected againstaccidental displacement or bending out of shape during the handling ofthe lamp and its insertion in and removal from a lamp socket.

Further objects and advantages of our invention will appear from thefollowing detailed description of species thereof and from theaccompanying drawing.

In the drawing,

FIG. 1 is an elevation of an electric incandescent lamp comprising ourinvention.

FIG. 2 is a longitudinal section of the lamp comprising our invention onthe line 22 of FIG. 1.

FIG. 3 is a transverse section through the lamp on the line 3-3 of FIG.1.

FIG. 4 is a perspective view showing a lamp according to our inventioninserted in place in a socket.

3,320,455 Patented May 16, 1967 FIG. 5 is a view showing one of the stempress ends of the lamp in section and inserted in place in one of thecontact clips of the lamp socket.

FIG. 6 is a fragmentary longitudinal sectional view of one end of amodified form of electric incandescent lamp comprising our invention.

FIG. 7 is a fragmentary perspective view of one end of the modified lampshown in FIG. 6, and

FIG. 8 is a transverse sectional view, on the line 88 of FIG. 6, of oneof the stem press ends of the modified lamp shown in FIGS. 6 and 7.

Referring to the drawing, the electric incandescent lamp there showncomprises a sealed elongated glass bulb or envelope 1 preferably oftubular shape and provided at its opposite ends with reduced diameterneck portions 2 terminating in flat stern press portions 3 through whichlead-in wires or conductors 4 are sealed so as to protrude endwisetherefrom. Interiorly of the bulb 1 the lead-in wires 4 are connected tothe opposite ends of an electrical energy translation element orfilament 5 of a suitable refractory metal and preferably in the form ofa straight length of coiled tungsten wire supported by the lead-in Wires4- in a position extending more or less axially of the tubularenvelope 1. The envelope 1 contains a suitable inert gas filling such asargon, for example, at a pressure below atmospheric.

As shown in FIG. 2, the protruding flat stem press portions 3 at theopposite ends of the envelope 1 are disposed in the same axial plane ofthe lamp envelope and are formed with shallow grooves or channelways 6of generally U or V-shape on one or both of their flat side faces '7.The said grooves 6 extend generally longitudinally of the envelope 1 andthey are located more or less centrally of the stem press portions 3between their side edges. The lead-in wires 4 project outwardly from theouter ends 3 of the stem press portions 4 at points likewise locatedmore or less centrally of the stern press portions, and they are bentback around the said ends 8 of the stem press portions to lie fiatagainst one or the other of the sides 7 thereof within the respectivegroove 6 therein so as to be concealed beneath the fiat surface 7 ofthat side of the stern press along which the lead-in Wire extends. Theportions 9 of the lead-in wires 4 thus bent around the stem pressportions and lying with- 45 .in the grooves 6 serve as the terminalcontacts for the lamp, and because of their concealment within thegrooves 6 so as to lie below the flat surfaces 7 of the stem pressportions 4, they are thereby protected against distortion by becomingcaught on objects and bent out of shape during the handling of the lampor its insertion and removal from the lamp socket. To permit theconcealment of the exposed terminal contact portions 9 of the lead-inwires 4 below the flat surfaces '7 of the stern press ortions 3, thegrooves 6 in the said stem press portions are made of a depth slightlygreater than the diameter of the said terminal contact wire portions 9.

Because of its particular structural conformation characterized by flatbase ends 3 provided with flush-type terminal contacts 9 concealed belowthe flat surfaces 7 of the base ends 3, the lamp according to theinvention is therefore readily adapted for use with exceedingly simpletype lamp sockets 10 (FIG. 4) similar to the clip type socketscustomarily employed for cartridge type fuses and comprising a pair ofspaced U-shaped metal clip contacts 11 mounted on an insulating base 12and adapted to receive the lamp therebetween and yieldably grip its fiatbase ends or stem press portions 3 so as to hold the lamp firmly inplace in the socket.

The lamp 1 is inserted in the socket 10 by simply pushing its flat baseends or stem press portions 3 straight down between the two spring arms13 of the respective contact clip 11 until opposed inward V-shapedindents or portions 14 of the spring arms 13 snap into the grooves 6 inthe flat base ends or stem press portions 3 of the lamp to thereby lockthe lamp in place in the socket, with the V-shaped indents 14 of one ofthe spring arms 13 of each clip 11 in spring pressure engagement withthe exposed portion 9 of the lead-in wire lying within the bottom of thegroove 6 in the stem press 3 so as to make effective electrical contacttherewith. As shown in FIGS. 3-5, the stem press portions 3 of the lampare preferably formed with double beveled side edges 3 to provideV-shaped wedge surfaces for facilitating the insertion of the stem pressportions of the lamp between the spring arms 13 of the socket clips 11.

Instead of the terminal contacts of the lamp being constituted byportions 9 of the lead-in wires bent back into the locating grooves 6 inthe stern press portions 3 of the lamp, the said terminal contacts maycomprise U-shaped metal clip members 15 straddling and suitably securedto the respective stem press portions 3 over the outer ends 8 and theflat sides 7 thereof, as shown in FIGS. 6 to 8. The clip members 15 maybe formed of sheet metal strips bent into U-sha-pe to provide twoparallel leg or arm portions 16 which fit snugly into channelways orpassageways 17 in the opposite fiat sides 7 of the stem press portions 3so as to lie flush with or below the fiat surfaces thereof, as shown inFIG. 8. The channelways 17 are deepened at their innermost ends to formcavities 18 which provide inwardly facing abutment shoulders 19, and thearms 16 of the clip 15 are formed with in-turned right-angledextremities 20 which extend into the cavities 18 of the channelways 17and engage with the abutment shoulders 19 to thereby lock the clip inplace on the stem press against unwarranted endwise withdrawaltherefrom. The metal clips 15 may be made out of springy material sothat they will function in the manner of a spring clip to cause the inturned lip ends 20 thereof to snap into place in the deepened portions18 of the channelways 1'7, and lock the clip in place on the stem press3, when the clip is pushed the full distance home into the channelways17. Instead of being formed out of springy material, the metal clips 15may be made of metal strip material which is merely flexible orbendable, and the metal strip material bent or deformed into placewithin the channelways 17 and into the deepened inner end portions orcavities 18 thereof.

In order to function as the terminal contacts of the lamp, the metalclips 15 are electrically connected in a suitable manner to therespective lead-in wire 4 to form composite electrical conductorstherewith. To this end, the metal clips may be each provided with acentral aperture 21 in that portion of the clip which lies opposite andstraddles the outer end of the stem press, and the lead-in wire 4 isthreaded through the said aperture 21 and suitably secured to the outerside of the metal clip as by soldering or welding it thereto, asindicated at 22.

The manufacture of a lamp constructed according to the invention may beaccomplished in a very simple manner by first sealing a lamp mount,comprising the filament 5 and lead-in wires 4 connected thereto, intoone end of a glass lamp envelope 1. The atmosphere within the envelope 1is then flushed out, and replaced by a filling of an inert gas such asargon, by directing a stream of the inert gas into the envelope throughits remaining open end. While the inert gas is thus being continuouslydirected into the open end of the envelope, the open neck end of theenvelope is then heated and softened, and compressed around the lead-inwire 4 of the mount, to thereby complete the sealing of the mount intothe envelope. The protruding portions 9 of the lead-in wires 4 are thenbent around the ends 8 of the stem press portions 3 to lie fiat withinthe bottoms of the respective grooves 6 in the stem press portions 3, orelse are soldered or otherwise connected to the U-shaped contact clips15 which are applied to the opposite ends of the envelope in the case ofthe modified form of lamp shown in FIGS. 63.

Although preferred embodiments of our invention have been disclosed, itwill be understood that the invention is not to be limited to thespecific construction and arrange ment of parts shown, but that they maybe widely modified within the spirit and scope of our invention asdefined by the appended claim.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

An electrical device comprising a double-ended sealed glass envelopeprovided at its opposite ends with protruding flattened external stempress portions disposed in a common plane, each of said flattened stempress portions having parallel channelways in its flat sides extendinglongitudinally of said envelope and disposed opposite one another,lead-in wires sealed through respective ones of said stem press portionsand extending into said envelope, and U-shaped metal clip membersstraddling the ends of and secured to said stem press portions withtheir arm portions snugly received within the said channelways in saidstem press portions and lying flush with the surfaces of the fiat sidesthereof, said metal clip members being electrically connected torespective ones of said lead-in wires to form terminal contacts for thedevice.

References Cited by the Examiner UNITED STATES PATENTS 693,222 2/1902Boehm 339-144 870,341 11/1907 Boehm 339144 2,705,310 3/1955 Hodge313-318 3,156,841 11/1964 Ayres 313-318 X ELI LIEBERMAN, PrimaryExaminer.

JOSEPH D. SEERS, HERMAN KARL SAALBACH,

ARTHUR GAUSS, GEORGE N. WESTBY,

Examiners.

S. CHATMON, 111., A. S. TRASK, Assistant Examiners.

